The params sent to the controller are not nesting correctly as seen below. <% fields_for "discount_code[new_discount][] ", task do |form| %> Tour Type ID: <%= form.text_field :tour_type_id %> Price: <%= form.text_field :price_number %> Days: <%= form.text_field :days %> <% end %> I would expect this to come into the controller looking like parameters : {"discount_code" => {"new_discount" => [ {"tour_type_id" => ''8'', "price_number" => ''8.00'', "days" => ''-1''}, {"tour_type_id" => ''7'', "price_number" => ''22.00'', "days" => ''3''} ] } Instead - it''s coming in like this: Parameters : {:discount_code => {"new_discount_attributes" =>[ {"tour_type_id"=>"7"}, {"day"=>"-1", "tour_type_id"=>"8"}, {"day"=>"3", "price_number"=>"22.00"}, {"price_number"=>"8.00"}], -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.